Like many people, from a young age I was obsessed and interested in works of fantasy and science fiction. To feel transported to magical worlds of various imaginative creatures and diverse places. The luxury of being able to separate from the mundanity of reality is one many children (or nostalgic adults) will be able to relate to upon reflection. Worlds that appear far more creative and engaging than our own are intrinsically enticing to the human psyche and the escapism it allows is no doubt an integral part of growing up for many people (especially those who have also dealt or avoided dealing with mental health issues).
The intricate connection to the (super)natural world drove me to fall in love with the natural world. Although there might seem to be an intrinsic contrast between the two – the absence or presence of reality – the truth is that the world is a wondrous place if you observe it through an appropriate lens. Dragons are real, forms of life are astronomically varied and imaginative, and there we are surrounded by the unknown and potentially mythical. To see the awe and mystification on a child’s face when they see a strange or unique animal for the very first time bears remarkable parallels to the expression when we stare into the fantasy of Avatar or The Lord of the Rings.
It might seem common for ‘nerds’ (at least under the traditional definition of being obsessed with particular aspects of pop culture) to later become scientists of some form or another. And I think this is a true reflection: particularly, I think the innate personality traits that cause one to look at the world of fantasy with wonder and amazement also commonly elicits a similar response in terms of the natural world. It is hard to see an example where the CGI’d majesty of contemporary fantasy and sci-fi could outcompete the intrigue generated by real, wondrous plants and animals.
Seeing the divine in the mundane
Although we often require a more tangible, objective justification for research, the connection of people to the diversity of life (whether said diversity is fictitious or not) should be a significant driving factor in the perceived importance of conservation management. However, we are often degraded to somewhat trivial discussions: why should we care about (x) species? What do they do for us? Why are they important?
If we approach the real world and the organisms that inhabit it with truly the same wonder as we approach the fantastical, would we be more successful in preserving biodiversity? Could we reverse our horrific trend of letting species go extinct? Every species on Earth represents something unique: a new perspective, an evolutionary innovation, a lens through which to see the world and its history. Even the most ‘mundane’ of species represent something critical to functionality of ecosystems, and their lack of emphasis undermines their importance.
The biota of Earth are no different to the magical fabled beasts of science fiction and fantasy, and we’re watching it all burn away right in front of our eyes.
The first major component that is needed for SDM is the occurrence data. Some methods will work with presence-only data: that is, a map of GPS coordinates which describes where that species has been found. Others work with presence-absence data, which may require including sites of known non-occurrence. This is an important aspect as the non-occurring sites defines the environment beyond the tolerance threshold of the species: however, it’s very likely that we haven’t sampled every location where they occur, and there will be some GPS co-ordinates that appear to be absent of our species where they actually occur. There are some different analytical techniques which can account for uneven sampling across the real distribution of the species, but they can get very technical.
Our SDM analysis of choice (e.g. MaxEnt) will then use various algorithms to build a model which best correlates where the species occurs with the environmental variables at those sites. The model tries to create a set of environmental conditions that best encapsulate the occurrence sites whilst excluding the non-occurrence sites from the prediction. From the final model, we can evaluate how strong the effect of each of our variables is on the distribution of the species, and also how well our overall model predicts the locality data.
Species distribution modelling continues to be a useful tool for conservation and evolution studies, and improvements in analytical algorithms, available environmental data and increased sampling of species will similarly improve SDM. Particularly, improvements in environmental projections from both the distant past and future will improve our ability to understand and predict how species will change, and have changed, with climatic changes
This is Part 1 of a four part miniseries on the process of speciation; how we get new species, how we can see this in action, and the end results of the process. This week, we’ll start with a seemingly obvious question: what is a species?
The definition of a ‘species’
‘Species’ are a human definition of the diversity of life. When we talk about the diversity of life, and the myriad of creatures and plants on Earth, we often talk about species diversity. This might seem glaringly obvious, but there’s one key issue: what is a species, anyway? While we might like to think of them as discrete and obvious groups (a dog is definitely not the same species as a cat, for example), the concept of a singular “species” is actually the result of human categorisation.
In reality, the diversity of life is spread across a huge spectrum of differentiation: from things which are closely related but still different to us (like chimps), to more different again (other mammals), to hardly relatable at all (bacteria and plants). So, what is the cut-off for calling something a species, and not a different genus, family, or kingdom? Or alternatively, at what point do we call a specific sub-group of a species as a sub-species, or another species entirely?
This might seem like a simple question: we look at two things, and they look different, so they must be different species, right? Well, of course, nature is never simple, and the line between “different” and “not different” is very blurry. Here’s an example: consider that you knew nothing about the history, behaviour or genetics of dogs. If you simply looked at all the different breeds of dogs on Earth, you might suggest that there are hundreds of species of domestic dogs. That seems a little excessive though, right? In fact, the domestic dog, Eurasian wolf, and the Australian dingo are all the same species (but different subspecies, along with about 38 others…but that’s another issue altogether).
For example, a horse and zebra can breed to produce a zorse, however zorse are fundamentally infertile (due to the different number of chromosomes between a horse and a zebra) and thus a horse is a different species to a zebra. However, a German Shepherd and a chihuahua can breed and make a hybrid mutt, so they are the same species.
To try and account for the issues with the BSC, taxonomists try to push for the usage of “integrative taxonomy”. This means that species should be defined by multiple different agreeing concepts, such as reproductive isolation, genetic differentiation, behavioural differences, and/or ecological traits. The more traits that can separate the two, the greater support there is for the species to be separated: if they disagree, then more information is needed to determine exactly whether or not that should be called different species. Debates about taxonomy are ongoing and are likely going to be relevant for years to come, but form critical components of understanding biodiversity, patterns of evolution, and creating effective conservation legislation to protect endangered or threatened species (for whichever groups we decide are species).
Emotion and spirituality are concepts that inherently seem at odds with the fundamentally stoic, empirical nature of scientific research. Science is based on a rigorous system of objectivity, repeatability and empiricism that, at face value, appears to completely disregard subjective aspects such as emotion, spirituality or religion. But in the same way that this drives the division of art from science, removing these subjective components of science can take away some of the personal significance and driving factors of scientific discipline.
Emotions as a driving force in science
For many scientists, emotional responses to inquiry, curiosity and connection are important components of their initial drive to study science in the first place. The natural curiosity of humanity, the absolute desire to know and understand the world around us, is fundamental to scientific advancement (and is a likely source of science as a concept in the first place). We care deeply about understanding many aspects of the natural world, and for many there is a strong emotional connection to our study fields. Scientists are fundamentally drawn to this career path based on some kind of emotional desire to better understand it.
Although it’s likely a massive cliché, Contactis one of my favourite science-fiction movies for simultaneously tackling faith, emotion, rationality, and scientific progress. And no doubt any literary student could dissect these various themes over and over and discuss exactly how the movie balances the opposing concepts of faith in the divine and scientific inquiry (and the overlap of the two). But for me, the most heartfelt aspect the movie is the portrayal of Ellie Arroway: a person who is insatiably driven to science, to the point of sacrificing many things in her life (including faith). But she’s innately an emotional person; when her perspectives are challenged by her observations, it’s a profound moment for her as a person. Ellie, to me, represents scientists pretty well: passionate, driven, idealistic but rational and objective as best as she can be. These traits make her very admirable (and a great protagonist, as far as I’m concerned).
I would not, under ordinary circumstances, consider myself to be particularly sentimental or spiritual. I don’t believe in many spiritual concepts (including theism, the afterlife, or concepts of a ‘soul’), and try to handle life as rationally and objectively as I can (sometimes not very successful given my mental health). But I can’t even remotely deny that there is a strong emotional or spiritual attachment to my field of science. Without delving too much into my own personal narrative (at the risk of being a little self-absorbed and pretentious; it’s also been covered a little in another post), the emotional connection I share with the life of Earth is definitely something that drove me to study biology and evolution. The sense of wonder and curiosity at observing the myriad of creatures and natural selection can concoct. The shared feeling of being alive in all of its aspects. The mystery of the world being seen through eyes very different to ours.
Although it’s of course always better to frame an argument or present research in an objective, rational matter, people have a tendency to respond well to appeal to emotion. In this sense, presenting scientific research as something that can be evocative, powerful and emotional is, in my belief, a good tactic to get the general public invested in science. Getting people to care about our research, our study species, and our findings is a difficult task but one that is absolutely necessary for the longevity and development of science at both the national and global level.
Pretending the science is emotionless and apathetic is counterproductive to the very things that drove us to do the science in the first place. Although we should attempt to be aware of, and distance, our emotions from the objective, data-based analysis of our research, admitting and demonstrating our passions (and why we feel so passionate) is critical in distilling science into the general population. Science should be done rationally and objectively but driven by emotional characteristics such as wonder, curiosity and fascination.
But the real question is: why are there so many endemics in Australia? What is so special about our country that lends to our unique flora and fauna? Although we naturally associate tropical regions with lush, vibrant and diverse life, most of Australia is complete desert. That said, most of our species are concentrated in the tropical regions of the country, particularly in the upper east coast and far north (the ‘Top End’).
There are a number of different factors which contribute to the high species diversity of Australia. Most notably is how isolated we are as a continent: Australia has been separated from most of the rest of the world for millions of years. In this time, the climate has varied dramatically as the island shifted northward, creating a variety of changing environments and unique ecological niches for species to specialise into. We refer to these species groups as ‘Gondwana relicts’, since their last ancestor with the rest of the world would have been distributed across the supercontinent Gondwana over 100 million years ago. These include marsupials, many birds groups (including ratites and megapodes), many fish groups and a plethora of others. A Gondwanan origin explains why they are only found within Australia, southern Africa and South America (the closest landmass that was also historically connected to Gondwana).
Early arrivals and naturalisation to the Australian ecosystem
Eventually, this connection also brought with them one of our most iconic species; the dingo. Estimates of their arrival dates the migration at around 6 thousand years ago. As Australia’s only ‘native’ dog, there has been much debate about its status as an Australian icon. To call the dingo ‘native’ implies it’s always been there: but 6 thousand years is more than enough time to become ingrained within the ecosystem in a stable fashion. So, to balance the debate (and prevent the dingo from being labelled as an ‘invasive pest’ unfairly), we often refer to them as ‘naturalised’. This term helps us to disentangle modern-day pests, many of which our immensely destructive to the natural environment, from other species that have naturally migrated and integrated many years ago.
Invaders of the Australian continent
Of course, we can never ignore the direct impacts of humans on the ecosystem. Particularly with European settlement, another plethora of animals were introduced for the first time into Australia; these were predominantly livestock animals or hunting-related species (both as predators and prey). This includes the cane toad, widely regarded as one of the biggest errors in pest control on the planet.
When European settlers in the 1930s attempted to grow sugar cane in the far eastern part of the country, they found their crops decimated by a local beetle. In an effort to eradicate them, they brought over a species of cane toad, with the idea that they would control the beetle population and all would be well. Only, cane toads are particularly lazy and instead of targeting the cane beetles, they just thrived on all the other native invertebrates around. They’re also very resilient and adaptable (and highly toxic), so their numbers exploded and they’ve since spread across a large swathe of the country. Their toxic skin makes them fatal food objects for many native predators and they strongly compete against other similar native animals (such as our own amphibians). The cane toad introduction of 1935 is the poster child of how bad failed pest control can be.
But is native always better?
History tells a very stark tale about the poor native animals and the ravenous, rampaging pest species. Because of this, it is a widely adopted philosophical viewpoint that ‘native is always best’. And while I don’t disagree with the sentiment (of course we need to preserve our native wildlife, and not the massively overabundant pests), there are rare examples where nature is a little more complicated. In Australia, this is exemplified in the noisy miner.
The noisy miner is a small bird which, much like its name implies, is incredibly noisy and aggressive. It’s highly abundant, found predominantly throughout urban and suburban areas, and seems to dominate the habitat. It does this by bullying out other bird species from nesting grounds, creating a monopoly on the resource to the exclusion of many other species (even larger ones such as crows and magpies). Despite being native, it seems to have thrived on human alteration of the landscape and is a serious threat to the survival and longevity of many other species. If we thought of it solely under the ‘nature is best’ paradigm, we would dismiss the noisy miner as ‘doing what it should be.’ The truth is really more of a philosophical debate: is it natural to let the noisy miner outcompete many other natives, possibly resulting in their extinction? Or is it only because of human interference (and thus is our responsibility to fix) that the noisy miner is doing so well in the first place? It’s not a simple question to answer, although the latter seems to be incredibly important.
The amazing biodiversity of Australia is a badge of honour we should wear with patriotic pride. Conservation efforts of our endemic fauna are severely limited by a lack of funding and resources, and despite a general acceptance of the importance of diverse ecosystems we remain relatively ineffective at preserving it. Understanding and connecting with our native wildlife, whilst finding methods to control invasive species, is key to conserving our wonderful ecosystems.